A comparative study of bacterial and parasitic intestinal infections in India

Non-typhoidal Salmonella in humans in India, Vietnam, Bangladesh and Sri Lanka: a systematic review

Objectives

Non-typhoidal Salmonella (NTS) commonly causes a self-limiting illness but invasive disease (iNTS) can be life-threatening. Antimicrobial resistance (AMR) increases the risk of mortality. This systematic review aimed to estimate the proportion of NTS isolated in those attending healthcare services, serovar burden, AMR, serovar-specific AMR, and case fatality rate (CFR) in India, Bangladesh, Sri Lanka and Vietnam.

Methods

The review included quantitative studies on NTS and AMR from 1980 to 2020 but excluded studies unrelated to humans or selected countries. Data were extracted from articles identified from Ovid SP, Web of Science, Wiley Cochrane Library, Elsevier Scopus and WHO Global Index Medicus. The Joanna Briggs Institute Critical Appraisal Tools Checklist for Prevalence Studies was used for risk-of-bias assessment. Meta-analyses were performed for the proportion of NTS isolated, the proportion of specific serovars isolated, percentage of AMR and CFR.

Results

Six thousand and twenty-six isolates (79 serovars) were identified from 73 studies, with Salmonella enterica serovar Typhimurium being the most common. Of the 73 selected studies, 46% were hospital/laboratory surveillance studies, examining the aetiology of invasive or non-invasive infections. The pooled proportion estimate for non-iNTS was 2.1% (95% CI: 1.2%-3.2%) and for iNTS was 0.3% (95% CI: 0.1%-0.5%). The pooled CFR was 14.9% (95% CI: 4.0%-29.6%). Pooled resistance estimates for ampicillin, ceftriaxone, chloramphenicol, ciprofloxacin, co-trimoxazole, nalidixic acid and azithromycin were calculated. MDR iNTS was less prevalent in India [22.3% (95% CI: 0.0%-66.8%)] than in Vietnam [41.2% (95% CI: 33.6%-49.3%)]. Heterogeneity of studies was high as the majority were observational surveillance studies.

Conclusions

Despite data scarcity in some countries, this review highlights the continued contribution of NTS infection to disease burden, compounded by high AMR rates.

Reduction in diarrhea cases following implementation of COVID-19 hand hygiene interventions in Ghana: A causal impact analysis

BACKGROUND

The human hand has constant contact with the environment, hence requires regular hand hygiene. Hand hygiene has gained recognition because of the COVID-19 pandemic and is a largely effective, affordable preventive measure against infectious diseases. This study used both national and sub-national analyses to evaluate the effect of COVID-19 handwashing guidelines on instances of diarrhea in Ghana.

METHODS

Data on diarrhea cases spanning February 2018 and March 2022 were retrieved from the District Health Information Management System (DHIMS 2) using a data extraction guide. The data were summarized using descriptive statistics. The difference in diarrhea cases between the pre-COVID-19 and COVID-19 periods was measured using a two-sample t-test across Ghana's 16 administrative areas. Causal Impact package in R statistical software was employed to determine the impact of the introduction of COVID-19 hand hygiene protocols on diarrheal disease.

RESULTS

A total of 5,645,533 diarrheal cases reported between February 2018 and March 2022 through the routine MIS (DHIMS2) were examined. Fifty-three percent of the cases occurred before the introduction of the hand hygiene protocol. Descriptive statistics indicated a statistically significant decrease in average diarrheal cases during the hand hygiene implementation era (13,463 cases reduction, p<0.001). Sub-national analyses revealed significant reductions in various regions: Greater Accra, Ashanti, Ahafo, Central, Eastern, Northern, Upper East, Upper West, and Volta (p<0.05). Causal impact analysis confirmed 11.0% nationwide reduction in diarrheal cases attributed to the COVID-19 hand hygiene protocols (p<0.001).

CONCLUSION

This study underscores the effectiveness of COVID-19 hand hygiene protocols in reducing diarrheal morbidity in Ghana, with varying regional impacts. These findings advocate for the sustenance of investments and commitments made at the COVID hand hygiene protocols, particularly in this era where the pandemic appears controlled.

Navigating a Complex Presentation: Management of Hypernatremic Dehydration, Acute Kidney Injury, Hyperkalemia, and Metabolic Acidosis in a Patient With Down Syndrome: A Case Report

Worldwide, gastroenteritis is a well-known cause of dehydration in pediatric patients and can be life-threatening due to subsequent electrolyte disturbance or dehydration itself. In this case, we present an infant with Down syndrome (karyotype: 21 trisomy) who presented to us with moderate hypernatremic dehydration associated with severe hyperkalemia, moderate metabolic acidosis (pH: 7.1, random blood glucose: 80-110 mg/dL), and elevated kidney function tests secondary to the gastroenteritis caused by Entamoeba histolytica infection. The patient is being followed up by the pediatrics genetics clinic for growth and development, with regular screening for thyroid and celiac diseases, and he has no major heart, gastrointestinal, or renal anomalies. This unique and complex presentation of electrolyte disturbance and dehydration associated with a susceptible condition of Down syndrome deserves special attention with precise management which can be challenging. We managed the patient as a case of hypernatremic dehydration with gradual correction of serum sodium and dehydration, while concurrently managing hyperkalemia by routine methods (beta agonist inhalers, insulin, dextrose 10%) with close laboratory and clinical monitoring at the pediatric intensive care unit. The pediatric nephrology team was also consulted while delineating the management plan. As the patient's condition eventually resolved with normal kidney function and electrolytes, metabolic acidosis also resolved, with good oral intake and urine output, stable vitals, and was discharged after 72 hours. In conclusion, this case showed that pediatric patients with susceptible conditions such as Down syndrome with gastroenteritis can present with a lethal combination of dehydration and/or electrolyte disturbance, making close monitoring and prompt management paramount in such cases.

Common Etiological Agents in Adult Patients with Gastroenteritis from Central Iran

Aims: This study represents the first analysis from Iran for both the frequency of the most common causes of infectious diarrhoea and their antibiotic resistance patterns in adult patients. Methods: Adult stool specimens (n = 211) were analyzed. Stool specimens were analyzed using standard microbiological, polymerase chain reaction, and reverse transcription polymerase chain reaction tests to identify bacterial, parasitic, and viral enteropathogens. Antibiotic resistance profiles were determined. Results: Enteropathogens were identified in 46.4% (98/211) of the surveyed samples. This included 33.1% (70/211) bacterial infections, including 9.9% (21/211) diarrheagenic Escherichia coli (DEC) and 8.5% (18/211) Shigella spp. We detected 7.1% (15/211) parasitic infections (mostly Giardia lamblia) and 6.1% (13/211) viral infections (mostly adenovirus). The DEC and Shigella spp. isolates included many multi-drug resistant (MDR) isolates (95.2% and 77.7%, respectively), and extended spectrum-β-lactamase (ESBL) genes were often present (57.1% and 61.1%, respectively). The most commonly identified ESBL genes in the DEC and Shigella spp. isolates were bla_TEM (100% in both species), bla_CTX-M15 (91.6% and 100%, respectively), AmpC bla_CIT (80% and 100%, respectively), and bla_DHA (80% and 100%, respectively). Conclusions: Bacterial infection was the primary cause of infectious diarrhea, affecting one-third of the adults. The frequency of DEC and Shigella spp. was higher than for other enteropathogens. The high prevalence of MDR, the elevated incidence of ESBL genes among Shigella spp. and DEC isolates, and the presence of quinolone resistance in the Salmonella spp. isolates represent a significant challenge for gastroenteritis diagnosis and treatment in this region.

Prevalence of Amoebiasis and Associated Complications in India: A Systematic Review

PURPOSE

Intestinal protozoan parasites are responsible for diarrheal diseases causing significant morbidity and mortality. Entamoeba histolytica is the principle protozoan parasite associated with diarrheal infections. The infection is often associated with inaccessibility to clean drinking water and poor sanitary conditions in low- and middle-income countries including India. A comprehensive systematic review was performed to evaluate a reliable nationwide estimate for prevalence and geographic distribution of amoebiasis in India and the complications associated with it.

METHODS

We used the PRISMA guidelines to perform a systematic review and meta-analysis of articles published between the year 2001-2020. Two English language databases PubMed and Web of Science were searched to achieve relevant studies.

RESULTS

Initial searches resulted in 467 studies out of which 64 eligible articles involving data from 289,659 human subjects from 12 states and 4 union territories were included in the final analysis. Prevalence of amoebiasis ranged from 3-23% in asymptomatic population, 0.64-11% in symptomatic patients and 1-17.5% in HIV-infected patients. Highest prevalence was seen in Tamil Nadu, Andaman Nicobar Island and North East India. Extra intestinal invasion of Entamoeba histolytica leading to complications such as amoebic liver abscess, amoebic colitis, colonic perforation and ameboma were also reported. Such complications have the potential to increase healthcare burden and may prove to be fatal.

CONCLUSION

Amoebiasis remains a significant public health issue in India responsible for diarrheal diseases causing significant morbidity and mortality. Entamoeba histolytica is the principle protozoan parasite associated with amoebiasis. Public health efforts should be directed towards its control and better diagnostic methods should be employed for distinguishing between pathogenic and non-pathogenic species of Entamoeba.

Association between Handwashing Behavior and Infectious Diseases among Low-Income Community Children in Urban New Delhi, India: A Cross-Sectional Study

Diarrheal diseases and respiratory infections (RI) are two leading causes of childhood mortality in low and middle-income countries. Effective handwashing at critical time-points may mitigate these diseases. However, there is a lack of published data investigating this association in school-aged children in India. This study is part of a larger prospective handwashing intervention study in a low-income community in New Delhi, India examining the associations between handwashing behavior and diarrhea and RI in schoolchildren. This current study reports the findings of the baseline survey administered to 272 mother–child dyads. Children aged 8–12 years, and their mothers, were recruited from six schools. A baseline questionnaire was used to collect sociodemographic data, handwash behavior, and mother-reported recent diarrhea and RI incidence among the children. Handwashing before and after preparing food, after defecation, and after cleaning dishes significantly reduced the odds of diarrhea by over 70%, and of RI by over 56%. Using a clean cloth after handwashing lowered odds of diarrhea and RI by 72% and 63% respectively. Around 60% of the participants believed that handwashing could prevent diarrhea and RI in their children. There was a low prevalence of handwashing at critical time-points and a poor perception regarding handwashing benefits. To improve handwashing behavior, hygiene promotion programs need to understand what motivates and hinders handwashing in vulnerable populations.

Comparative analysis of virulence determinants, phylogroups, and antibiotic susceptibility patterns of typical versus atypical Enteroaggregative E. coli in India

Enteroaggregative Escherichia coli (EAEC) is an evolving enteric pathogen that causes acute and chronic diarrhea in developed and industrialized nations in children. EAEC epidemiology and the importance of atypical EAEC (aEAEC) isolation in childhood diarrhea are not well documented in the Indian setting. A comparative analysis was undertaken to evaluate virulence, phylogeny, and antibiotic sensitivity among typical tEAEC versus aEAEC. A total of 171 EAEC isolates were extracted from a broad surveillance sample of diarrheal (N = 1210) and healthy children (N = 550) across North India. Polymerase chain reaction (PCR) for the aggR gene (master regulator gene) was conducted to differentiate tEAEC and aEAEC. For 21 virulence genes, we used multiplex PCR to classify possible virulence factors among these strains. Phylogenetic classes were identified by a multiplex PCR for chuA, yjaA, and a cryptic DNA fragment, TspE4C2. Antibiotic susceptibility was conducted by the disc diffusion method as per CLSI guidelines. EAEC was associated with moderate to severe diarrhea in children. The prevalence of EAEC infection (11.4%) was higher than any other DEC group (p = 0.002). tEAEC occurrence in the diarrheal group was higher than in the control group (p = 0.0001). tEAEC strain harbored more virulence genes than aEAEC. astA, aap, and aggR genes were most frequently found in the EAEC from the diarrheal population. Within tEAEC, this gene combination was present in more than 50% of strains. Also, 75.8% of EAEC strains were multidrug-resistant (MDR). Phylogroup D (43.9%) and B1 (39.4%) were most prevalent in the diarrheal and control group, respectively. Genetic analysis revealed EAEC variability; the comparison of tEAEC and aEAEC allowed us to better understand the EAEC virulence repertoire. Further microbiological and epidemiological research is required to examine the pathogenicity of not only typical but also atypical EAEC.

Enteroaggregative E. coli (EAEC) are an increasingly important cause of diarrhea. E. coli belonging to this category cause watery diarrhea, which is often persistent and can be inflammatory. It is also associated with traveler’s diarrhea in children and adults in middle and high-income countries. EAEC are defined by their ability to adhere to epithelial cells in a characteristic stacked brick-like pattern. However, the identification of these pathogenic strains remains elusive because of its heterogeneous nature. Genes that could contribute to the pathogenicity of EAEC encode adhesions, toxins, and other factors. Due to the heterogeneity of EAEC strains and differing host immune responses, not all EAEC infections are symptomatic. A critical factor in both recognizing EAEC pathogenesis and defining typical EAEC (tEAEC) strains is AggR, a transcriptional control for many EAEC virulence genes. The central role of aggR in virulence confers a strong priority to understand its pathogenicity. To identify EAEC, the CVD432 probe has been used. The CVD432 is a DNA probe from pAA plasmid of EAEC, has been reported to be specific for the detection of EAEC. The lack of sensitivity comes from the genetic heterogeneity of the EAEC strains and the wide geographic dispersal of strains. In our study, we performed a large surveillance of EAEC from North India among the pediatric population. Samples were collected by the microbiology staff at the Postgraduate Institute of Medical Education and Research (PGIMER) and referral system labs in Chandigarh (Manimajra), Punjab (Ludhiana), Haryana (Panchkula and Ambala Cantt), Himachal Pradesh (Hamirpur, Shimla, and Tanda), and Uttarakhand (Rishikesh, Rudrapur, and Haridwar)]. PGIMER is the largest tertiary care hospital in North India and serves patients from across Punjab, Jammu and Kashmir, Himachal Pradesh and Haryana. EAEC infections were detected using molecular methods. In our finding, astA, aap, and aggR genes were most frequently found in the EAEC from the diarrheal population. Within tEAEC, this gene combination is present in more than 50% of strains and helps to differentiate tEAEC from aEAEC. Our collection of EAEC strains helps in finding an appropriate marker for the early detection of EAEC. Our signature sequence (astA, aap, and aggR) will be ideal as focus genes for EAEC identification, as well as tEAEC and aEAEC. The multidrug resistance (MDR) was observed in 75.8% of the EAEC strains. tEAEC exhibits resistance to a greater number of antibiotics with respect to aEAEC. The phylogenetic analysis revealed that EAEC phylogeny is diverse and dispersed in all the phylogroups.

Antimicrobial Resistance and Presence of Class 1 Integrons Among Different Serotypes of Salmonella spp. Recovered From Children with Diarrhea in Tehran, Iran

BACKGROUND

Salmonellosis is a major food-borne disease worldwide. The increasing prevalence of antimicrobial resistance among food-borne pathogens such as Salmonella spp. is concerning.

OBJECTIVE

The main objective of this study is to identify class 1 integron genes and to determine antibiotic resistance patterns among Salmonella isolates from children with diarrhea.

METHODS

A total of 30 Salmonella isolates were recovered from children with diarrhea. The isolates were characterized for antimicrobial susceptibility and screened for the presence of class 1 integron genes (i.e. intI1, sulI1, and qacEΔ1).

RESULTS

The most prevalent serotype was Enteritidis 36.7%, followed by Paratyphi C (30%), and Typhimurium (16.7%). The highest rates of antibiotic resistance were obtained for nalidixic acid (53.3%), followed by streptomycin (40%), and tetracycline (36.7%). Regarding class 1 integrons, 36.7%, 26.7%, and 33.3% of the isolates carried intI1, SulI, and qacEΔ1, respectively, most of which (81.8%) were multidrug-resistant (MDR). Statistical analysis revealed that the presence of class 1 integron was significantly associated with resistance to streptomycin and tetracycline (p = 0.042). However, there was no association between class 1 integron and other antibiotics used in this study (p > 0.05).

CONCLUSION

The high frequency of integron class 1 gene in MDR Salmonella strains indicates that these mobile genetic elements are versatile among different Salmonella serotypes, and associated with reduced susceptibility to many antimicrobials.